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Publisher: Elsevier   (Total: 3030 journals)

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Showing 1 - 200 of 3030 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 20, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 16, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 79, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 22, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 27, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 303, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription  
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 196, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 9, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 21, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 5, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
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Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 4)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 5)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 120, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 8, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 24, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 6, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 21, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 26, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 24, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 8, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 4)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 39, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 25, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 38, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 41, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 18, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 33, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 4)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 7, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 5, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 6, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 3)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 7, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 20, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 14)
Advances in Pharmacology     Full-text available via subscription   (Followers: 13, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 7, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 17, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 56)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 1, SJR: 0.1, h-index: 2)
Advances in Space Research     Full-text available via subscription   (Followers: 332, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 7)
Advances in Surgery     Full-text available via subscription   (Followers: 6, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 28, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 14)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 42, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 5, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 304, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 4, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 7, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 390, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 29, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 36, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 1)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 48, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 3, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 9, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 5)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access  
Algal Research     Partially Free   (Followers: 7, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 5, SJR: 0.776, h-index: 35)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 6, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 45, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 5)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 3)
American Heart J.     Hybrid Journal   (Followers: 45, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 47, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 34, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 6, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 32, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 25, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 31, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 48, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 174, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 51, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 2)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 22, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 23, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 21, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 32, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 13, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 5)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 52, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 3)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 2, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 38, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 154, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 7, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 10)
Anesthésie & Réanimation     Full-text available via subscription  
Anesthesiology Clinics     Full-text available via subscription   (Followers: 21, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 143, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)
Animal Reproduction Science     Hybrid Journal   (Followers: 5, SJR: 0.711, h-index: 78)
Annales d'Endocrinologie     Full-text available via subscription   (SJR: 0.394, h-index: 30)
Annales d'Urologie     Full-text available via subscription  
Annales de Cardiologie et d'Angéiologie     Full-text available via subscription   (SJR: 0.177, h-index: 13)
Annales de Chirurgie de la Main et du Membre Supérieur     Full-text available via subscription  
Annales de Chirurgie Plastique Esthétique     Full-text available via subscription   (Followers: 2, SJR: 0.354, h-index: 22)
Annales de Chirurgie Vasculaire     Full-text available via subscription   (Followers: 1)

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Journal Cover Aeolian Research
  [SJR: 0.973]   [H-I: 22]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1875-9637
   Published by Elsevier Homepage  [3030 journals]
  • Eolianite and coquinite as evidence of MIS 6 and 5, NW Black Sea coast,
           Turkey
    • Authors: Ahmet Evren Erginal; Nafiye Güneç Kıyak; Hamit Haluk Selim; Mustafa Bozcu; Muhammed Zeynel Öztürk; Yunus Levent Ekinci; Alper Demirci; Elmas Kırcı Elmas; Tuğba Öztürk; Çağlar Çakır; Mustafa Karabıyıkoğlu
      Pages: 1 - 9
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Ahmet Evren Erginal, Nafiye Güneç Kıyak, Hamit Haluk Selim, Mustafa Bozcu, Muhammed Zeynel Öztürk, Yunus Levent Ekinci, Alper Demirci, Elmas Kırcı Elmas, Tuğba Öztürk, Çağlar Çakır, Mustafa Karabıyıkoğlu
      This paper discusses the implications of a lowstand carbonate eolianite and overlying transgressive sequence of coquinite at Şile on the Turkish Black Sea coast based on composition, depositional characteristics and optical age estimations. The cross-bedded eolianite is a mixed ooid quartz grainstone in composition, yielding a depositional age matching MIS 6. It formed at the backshore of the paleobeach with the supply of sediment the from the beach face and offering insights into the drift of mixed shallow marine carbonates and siliciclastics together with radial ooids by onshore winds from a subaerially exposed high- to low-energy ooid shoals and oolitic sand complexes which developed parallel to the shoreline on the shallow shelf margin. During this lowstand, a low-relief dune retaining a record of opposing paleowind directions than that of prevalent northeasterly winds of today appears to have been lithified to form dune rock (aeolinite) under drier conditions compared to the present. Coinciding with MIS 5e, shallow marine coquina beds resting unconformably on the eolianite indicate the occurrence of the Mediterranean transgression during the last interglacial, as confirmed by benthic foraminifera within the high-salinity tolerant coquina shells.

      PubDate: 2017-02-17T10:08:03Z
      DOI: 10.1016/j.aeolia.2017.01.004
      Issue No: Vol. 25 (2017)
       
  • An efficient, self-orienting, vertical-array, sand trap
    • Authors: Michael Hilton; Bill Nickling; Sarah Wakes; Douglas Sherman; Teresa Konlechner; Mark Jermy; Patrick Geoghegan
      Pages: 11 - 21
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Michael Hilton, Bill Nickling, Sarah Wakes, Douglas Sherman, Teresa Konlechner, Mark Jermy, Patrick Geoghegan
      There remains a need for an efficient, low-cost, portable, passive sand trap, which can provide estimates of vertical sand flux over topography and within vegetation and which self-orients into the wind. We present a design for a stacked vertical trap that has been modelled (computational fluid dynamics, CFD) and evaluated in the field and in the wind tunnel. The ‘swinging’ trap orients to within 10° of the flow in the wind tunnel at 8ms−1, and more rapidly in the field, where natural variability in wind direction accelerates orientation. The CFD analysis indicates flow is steered into the trap during incident wind flow. The trap has a low profile and there is only a small decrease in mass flow rate for multiple traps, poles and rows of poles. The efficiency of the trap was evaluated against an isokinetic sampler and found to be greater than 95%. The centre pole is a key element of the design, minimally decreasing trap efficiency. Finally, field comparisons with the trap of Sherman et al. (2014) yielded comparable estimates of vertical sand flux. The trap described in this paper provides accurate estimates of sand transport in a wide range of field conditions.

      PubDate: 2017-02-17T10:08:03Z
      DOI: 10.1016/j.aeolia.2017.01.003
      Issue No: Vol. 25 (2017)
       
  • A wind tunnel study of the aerodynamic and sand trapping properties of
           porous mesh 3-dimensional roughness elements
    • Authors: J.A. Gillies; W.G. Nickling; G. Nikolich; V. Etyemezian
      Pages: 23 - 35
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): J.A. Gillies, W.G. Nickling, G. Nikolich, V. Etyemezian
      The aerodynamic drag properties and sand trapping effectiveness of porous roughness elements constructed of wire mesh with two geometries, cube/rectangular cylinder and round cylinder were evaluated in a wind tunnel study. Porosity of the mesh was 0.525. Volumetric porosity and permeability were systematically changed by nesting similar shaped but smaller sized forms within the largest forms for both shapes. Drag curves for both forms show dependence on Reynolds number to 70,000, due to the creation of complex transitional flow conditions in different zones within the forms. Length of sand deposits in the lee of the elements scale with permeability of the form and the trapping efficiency for particles within the forms scales with the cumulative area of the surfaces perpendicular to the directions of air flow. The cube/rectangular cylinder form was more effective at trapping sand than the round cylinder forms for the same saltation flux. The demonstrated effect of porosity and cumulative mesh area on aerodynamic drag and sand trapping effectiveness argues convincingly that porous elements have a greater potential than solid elements for modulating the sand flux to a higher degree than solid elements when used in large spatial arrays to control wind erosion.

      PubDate: 2017-02-17T10:08:03Z
      DOI: 10.1016/j.aeolia.2017.02.001
      Issue No: Vol. 25 (2017)
       
  • Laser particle counter validation for aeolian sand transport measurements
           using a highspeed camera
    • Authors: Leonardo Duarte-Campos; Kathelijne M. Wijnberg; Loreto Oyarte-Gálvez; Suzanne J.M.H. Hulscher
      Pages: 37 - 44
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Leonardo Duarte-Campos, Kathelijne M. Wijnberg, Loreto Oyarte-Gálvez, Suzanne J.M.H. Hulscher
      Measuring aeolian sand transport rates in the field has been a long-standing challenge. In this paper, we present the results of a laboratory experiment to test the ability of a laser particle counter sensor (Wenglor) to accurately count sand grains of various grain size classes and stainless steel beads. We compared the count data collected by the Wenglor with images from a Highspeed camera which revealed the actual number of grains passing the laser beam. A Silicon photodiode was used to record the laser intensity reduction induced by the sand grain passage through the laser beam to derive the minimal necessary reduction for the Wenglor to count grains. For the two possible settings of the Wenglor, i.e., Minimal Teach-in or Normal Teach-in, a minimum of 18% and 78% blocking of the laser beam was required for recording a count. This implies that the minimum grain size that can be observed by the Wenglor is 210 ± 3 μ m and 495 ± 10 μ m for the two settings respectively, which is considerably coarser than previously assumed. Due to the non-uniform power distribution of the laser sensor intensity, at the detection limit of 210μm, only grains passing through the centre of the beam will be counted.

      PubDate: 2017-02-24T10:39:08Z
      DOI: 10.1016/j.aeolia.2017.02.002
      Issue No: Vol. 25 (2017)
       
  • Complexity confers stability: Climate variability, vegetation response and
           sand transport on longitudinal sand dunes in Australia’s deserts
    • Authors: Paul P. Hesse; Matt W. Telfer; Will Farebrother
      Pages: 45 - 61
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Paul P. Hesse, Matt W. Telfer, Will Farebrother
      The relationship between antecedent precipitation, vegetation cover and sand movement on sand dunes in the Simpson and Strzelecki Deserts was investigated by repeated (up to four) surveys of dune crest plots (≈25×25m) over a drought cycle (2002–2012) in both winter (low wind) and spring (high wind). Vegetation varied dramatically between surveys on vegetated and active dune crests. Indices of sand movement had significant correlations with vegetation cover: the depth of loose sand has a strong inverse relationship with crust (cyanobacterial and/or physical) while the area covered by ripples has a strong inverse relationship with the areal cover of vascular plants. However, the relationship between antecedent rainfall and vegetation cover was found to be complex. We tentatively identify two thresholds; (1) >10mm of rainfall in the preceding 90days leads to rapid and near total cover of crust and/or small plants <50cm tall, and (2) >400mm of rainfall in the preceding three years leads to higher cover of persistent and longer-lived plants >50cm tall. These thresholds were used to predict days of low vegetation cover on dune crests. The combination of seasonality of predicted bare-crest days, potential sand drift and resultant sand drift direction explains observed patterns of sand drift on these dunes. The complex vegetation and highly variable rainfall regime confer meta-stability on the dunes through the range of responses to different intervals of antecedent rainfall and non-linear growth responses. This suggests that the geomorphic response of dunes to climate variation is complex and non-linear.

      PubDate: 2017-02-24T10:39:08Z
      DOI: 10.1016/j.aeolia.2017.02.003
      Issue No: Vol. 25 (2017)
       
  • Loess deposits of the upper Hanjiang River valley, south of Qinling
           Mountains, China: Implication for the pedogenic dynamics controlled by
           paleomonsoon climate evolution
    • Authors: Peini Mao; Jiangli Pang; Chunchang Huang; Xiaochun Zha; Yali Zhou; Yongqiang Guo
      Pages: 63 - 77
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Peini Mao, Jiangli Pang, Chunchang Huang, Xiaochun Zha, Yali Zhou, Yongqiang Guo
      Aeolian deposits in the Chinese Loess Plateau (CLP) provide a detailed archive for reconstructing the pedogenic intensity as well as the East Asian monsoon climate change. However, study on the loess in the upper Hanjiang River valley, south of Qinling Mountains has seldom been comprehensively reported. Located at the transition zone between temperate and subtropical monsoon climate, the study area is more sensitive to the climate change. In this paper, three loess-paleosol profiles at the first terrace of the upper Hanjiang River were studied in detail. High-resolution investigations, including field observations, optically stimulated luminescence (OSL) dating, and measurements of magnetic susceptibility (MS), grain-size (GS), color variation, loss-on-ignition (LOI) and chemical elements were carried out. The results show that the stratigraphic sequences, in order from the top to the bottom, are topsoil (TS), recent loess (L0), paleosol (S0), transitional loess (Lt), Malan loess (L1) and fluvial deposits (T1-al). The pedogenic intensity varies significantly in different layers and presents such a tendency of S0 >L0 >Lt>L1. This indicates four distinct stages in the paleoclimate evolution: a cold-dry period (55.0–11.5ka B.P.); a phase of gradual transition to warm-wet (11.5–8.5ka B.P.); the maximum warm-wet period (8.5–3.0ka B.P.); and a phase of gradually shifting to cool-dry (3.0–0.0ka B.P.). The climate change trends are similar with the loess records from the CLP and the stalagmite and peat records in southern China. But the paleosol development in the study is probably a better indicator of the strength of summer monsoon climate change during the mid-Holocene Climatic Optimum. This study also provides basic data for exploring the pedogenesis and climate differences in the East Asian monsoon climate zones.

      PubDate: 2017-03-28T10:58:48Z
      DOI: 10.1016/j.aeolia.2017.03.001
      Issue No: Vol. 25 (2017)
       
  • Suspended dust particle characteristics during an sandstorm on 29 February
           2008 in Minqin area, China
    • Authors: KeJie Zhan; ShiZeng Liu; ZiHui Yang; ETian Fang; LanPing Zhou; QiangQiang Wang; ShuJiang Guo; JianHui Zhang; Ning Huang
      Pages: 79 - 86
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): KeJie Zhan, ShiZeng Liu, ZiHui Yang, ETian Fang, LanPing Zhou, QiangQiang Wang, ShuJiang Guo, JianHui Zhang, Ning Huang
      Aeolian dust is one of the main aerosols in the troposphere, and plays an important role in the Earth’s climate system. In this study, detailed meteorological conditions and dust particle diameters were measured at three sites with different landscape characteristics in the Minqin oasis area of northwest China, on 29 February 2008. We show that as dust storms progressed through the desert into the oasis, variation in the character of the underlying land surface not only influenced the wind profile by modifying the frictional velocity of air (U∗), aerodynamic roughness length (Z0), horizontal sediment flux, and dust concentration of the near surface sublayer (1–49m), but it also changed the vertical structure of the aeolian sediment transport pattern. The particle size frequency distributions at three distinct sites were all unimodal, comprising a large number of aeolian dust particles with sizes less than 63μm (more than 65%). During transport, dust particle populations shifted to smaller sizes. Clearly, the influence of landform, windbreaks, and vegetation cover on horizontal sand-dust flux decreased with height as well as increasing particle size, with smaller aeolian particles being more easily captured by windbreaks, and vegetation.

      PubDate: 2017-04-18T11:55:51Z
      DOI: 10.1016/j.aeolia.2017.04.002
      Issue No: Vol. 25 (2017)
       
  • Trace-element concentrations and water-soluble ions in size-segregated
           dust-borne and soil samples in Sistan, southeast Iran
    • Authors: Reza Dahmardeh Behrooz; Abbas Esmaili-Sari; Nader Bahramifar; D.G. Kaskaoutis; Keivan Saeb; Fatemeh Rajaei
      Pages: 87 - 105
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Reza Dahmardeh Behrooz, Abbas Esmaili-Sari, Nader Bahramifar, D.G. Kaskaoutis, Keivan Saeb, Fatemeh Rajaei
      This study analyzes the chemical composition (water-soluble ions and trace elements) of the total suspended particles (TSP) and particulate matter less than 10 and 2.5µm (PM10 and PM2.5) in the Sistan basin, southeast Iran during the dusty and windy period June – October 2014. Extreme TSP, PM10 and PM2.5 concentrations, means of 1624.8, 433.4 and 320.8µgm−3, respectively, were recorded in the Zabol sampling site, while the examined water-soluble ions and trace metals constitute small fractions (∼4.1%–17.7%) of the particulate masses. Intense winds on the dust-storm days result in weathering of soil crust and deflation of evaporate minerals from the dried Hamoun lake beds in the Sistan basin. The soil samples are rich in Ca2+, SO4 2−, Na+ and Cl− revealing the existence of non-sea salts, as well as in Al, Fe and Mg, while the similarity in the chemical composition between soil and airborne samples indicates that the dust events over Sistan are local in origin. In contrast, low concentrations of secondary ions (i.e., nitrate) and heavy metals (i.e., Pb, Cr, Ni, Cu) indicate less anthropogenic and industrial emissions. Enrichment Factor analysis for TSP, PM10 and PM2.5 reveals that the anthropogenic sources contribute a substantial amount in the heavy metals rather than soil crust, while Al, Fe, Sn, Mg are mostly of crustal origin. The results provide essential knowledge in atmospheric chemistry over Sistan and in establishing mitigation strategies for air pollution control.

      PubDate: 2017-04-18T11:55:51Z
      DOI: 10.1016/j.aeolia.2017.04.001
      Issue No: Vol. 25 (2017)
       
  • Coastal dune activity and foredune formation on Moreton Island, Australia,
           1944–2015
    • Authors: Noam Levin; Pierre-Elie Jablon; Stuart Phinn; Kerry Collins
      Pages: 107 - 121
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Noam Levin, Pierre-Elie Jablon, Stuart Phinn, Kerry Collins
      The stabilization process of coastal dunes is complex, involving feedback mechanisms and lag times between changes in climatic conditions, vegetation establishment and dune movement. In this study our aim was to examine changes in dune activity and in the establishment of foredunes on Moreton Island, Australia. We used historical aerial photos, satellite images and Lidar data to quantify changes in bare sand areas, dune movement rates, foredune development and coastline changes between 1944 and 2015. We used wind data (1957–2016), to quantify changes in sand drift potential (DP) and in wind directionality, and wave data (1977–2016) to examine changes in wave height and wave direction. We found that transgressive dunes on Moreton Island have started stabilizing in the early 1970s, after a series of continuous foredunes developed on the eastern coast of Moreton Island, in spite of the increase in DP values. Foredunes have started establishing in the 1960s and 1970s during a period of lower wave height and decreased wind directionality. Once established, these foredunes have diminished sand supply to the transgressive dunes, causing a phase shift in the state of dune activity on the island. Coastal dune activity should therefore be examined over time scales of several decades at least, in order to quantify trends and to understand the underlying and causes to observed processes. Understanding the factors responsible for foredune formation is important for explaining dune stabilization on Moreton Island.

      PubDate: 2017-04-18T11:55:51Z
      DOI: 10.1016/j.aeolia.2017.03.005
      Issue No: Vol. 25 (2017)
       
  • Comments on ‘Influence of measurement uncertainties on fractional
           solubility of iron in mineral aerosols over the oceans’ Aeolian Research
           22, 85–92
    • Authors: Robert Raiswell; Jon R. Hawkings; Liane G. Benning; Samuel Albani; Natalie Mahowald
      Pages: 123 - 125
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Robert Raiswell, Jon R. Hawkings, Liane G. Benning, Samuel Albani, Natalie Mahowald


      PubDate: 2017-04-18T11:55:51Z
      DOI: 10.1016/j.aeolia.2017.03.003
      Issue No: Vol. 25 (2017)
       
  • Magnetic susceptibility of surface soils in the Mu Us Desert and its
           environmental significance
    • Authors: Xiaokang Liu; Ruijie Lu; Zhiqiang Lü; Jing Du; Feifei Jia; Tengfei Li; Lu Chen; Yongqiu Wu
      Pages: 127 - 134
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Xiaokang Liu, Ruijie Lu, Zhiqiang Lü, Jing Du, Feifei Jia, Tengfei Li, Lu Chen, Yongqiu Wu
      Magnetic susceptibility has been widely used as a climatic proxy in paleoclimatic research. In arid and semi-arid regions, the magnetic properties of modern surface soil are significantly influenced by precipitation. This is demonstrated by observed positive correlations between percentage frequency-dependent magnetic susceptibility (χfd%), which reflects the presence of fine-grained (superparamagnetic, SP) grains produced during weathering and pedogenesis, and regional mean annual precipitation (MAP). To further investigate this relationship, we measured the magnetic properties of 104 surface soil samples collected along two transects (AA and BB) spanning a rainfall gradient across the Mu Us Desert in northern China. There were no systematic trends in magnetic properties along transect BB; the χfd% values remained relatively low and stable, probably reflecting weak pedogenesis and the domination of the magnetic properties by lithology. In contrast, along transect AA there was a significant positive correlation (p<0.01) between χfd% and regional MAP. From this relationship, we developed a transfer function (P=274.1+1424.4×χfd%) and used it to produce quantitative estimates of paleo-precipitation within three Holocene aeolian sections located in the southern the modern Mu Us Desert. The results show that the variations of reconstructed precipitation are consistent with those of lithological properties, and they also confirm previous conclusions that paleosol development in the study area is dominated by precipitation. Overall the results further demonstrate the feasibility of using frequency-dependent magnetic susceptibility to quantitatively reconstruct regional paleo-precipitation, including within a geographically diverse desert area. In addition, they provide an improved understanding of the main sand provenance in Mu Us Desert.

      PubDate: 2017-04-25T12:01:32Z
      DOI: 10.1016/j.aeolia.2017.04.003
      Issue No: Vol. 25 (2017)
       
  • Field measurements on spatial variations in aeolian sediment availability
           at the Sand Motor mega nourishment
    • Authors: Bas Hoonhout; Sierd de Vries
      Pages: 93 - 104
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Bas Hoonhout, Sierd de Vries
      Spatial variations in aeolian sediment transport were measured at the Sand Motor mega nourishment in The Netherlands during a six week field campaign in the fall of 2014. A consistent significant increase in sediment transport in downwind direction (positive gradient) was measured over the intertidal beach area, indicating that the intertidal beach is a primary source of aeolian sediment, despite the high soil moisture contents. A small positive increase in transport in downwind direction was measured over the dry beach, indicating that local aeolian sediment supply was hampered. A consistent decrease in sediment transport in downwind direction (negative gradient) was measured at the transition between intertidal and dry beach, indicating local deposition of sediment. The negative gradients coincide with the berm edge and the onset of a shell pavement. Therefore deposition might be promoted by morphological feedback between a berm and the wind and the entrapment of sediment in the beach armor layer. The local sediment deposits cause the sediment supply to the dunes to be continued even during high water, resulting in a phased process. The influence of the beach armor layer reduces during storm events as the armor layer itself is being mobilized.

      PubDate: 2017-01-09T03:51:16Z
      DOI: 10.1016/j.aeolia.2016.12.003
      Issue No: Vol. 24 (2017)
       
  • Understanding dust emission in the Bodélé region by extracting locally
           mobilized dust aerosols from satellite Aerosol Optical Depth data using
           principal component analysis
    • Authors: Sagar Prasad Parajuli; Zong-Liang Yang
      Pages: 105 - 113
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Sagar Prasad Parajuli, Zong-Liang Yang
      Despite the increasing availability of satellite and ground-based Aerosol Optical Depth (AOD) data, their application in dust modeling is limited because these data do not differentiate locally mobilized dust from remotely advected dust and other aerosols. In this work, we extract the locally mobilized Dust Optical Depth (DOD) in the Bodélé region from historical AOD data through a principal component analysis of wind speed and AOD time series (2003–2012). Principal component analysis effectively identifies the correlated signature between wind speed and AOD making it possible to separate the dust component from AOD data. Using the reconstructed DOD, we then study the effect of key environmental variables, namely wind speed, soil moisture, soil temperature, vegetation, and boundary layer height on dust emission. Results show that all of these environmental variables are significantly correlated with the reconstructed DOD indicating their association with the dust emission process. The extraction technique described in this study can be extended to regional and global scales to identify the dust sources which are not adequately represented in regional and global dust models.

      PubDate: 2017-01-09T03:51:16Z
      DOI: 10.1016/j.aeolia.2017.01.001
      Issue No: Vol. 24 (2017)
       
  • Sensitivity of WRF-chem predictions to dust source function specification
           in West Asia
    • Authors: Seyed Omid Nabavi; Leopold Haimberger; Cyrus Samimi
      Pages: 115 - 131
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Seyed Omid Nabavi, Leopold Haimberger, Cyrus Samimi
      Dust storms tend to form in sparsely populated areas covered by only few observations. Dust source maps, known as source functions, are used in dust models to allocate a certain potential of dust release to each place. Recent research showed that the well known Ginoux source function (GSF), currently used in Weather Research and Forecasting Model coupled with Chemistry (WRF-chem), exhibits large errors over some regions in West Asia, particularly near the IRAQ/Syrian border. This study aims to improve the specification of this critical part of dust forecasts. A new source function based on multi-year analysis of satellite observations, called West Asia source function (WASF), is therefore proposed to raise the quality of WRF-chem predictions in the region. WASF has been implemented in three dust schemes of WRF-chem. Remotely sensed and ground-based observations have been used to verify the horizontal and vertical extent and location of simulated dust clouds. Results indicate that WRF-chem performance is significantly improved in many areas after the implementation of WASF. The modified runs (long term simulations over the summers 2008–2012, using nudging) have yielded an average increase of Spearman correlation between observed and forecast aerosol optical thickness by 12–16 percent points compared to control runs with standard source functions. They even outperform MACC and DREAM dust simulations over many dust source regions. However, the quality of the forecasts decreased with distance from sources, probably due to deficiencies in the transport and deposition characteristics of the forecast model in these areas.

      PubDate: 2017-01-16T04:41:38Z
      DOI: 10.1016/j.aeolia.2016.12.005
      Issue No: Vol. 24 (2017)
       
  • A quantitative evaluation of the 3–8 July 2009 Shamal dust storm
    • Authors: Mehdi Hamidi; Mohammad Reza Kavianpour; Yaping Shao
      Pages: 133 - 143
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Mehdi Hamidi, Mohammad Reza Kavianpour, Yaping Shao
      In this paper, a quantitative evaluation of the severe dust storm which occurred in the Middle East during 3–8 July 2009 is presented. The quantification is based on the numerical simulation using the WRF/Chem-D model which has been verified and calibrated for the Middle East region. It is found that, during the 3–8 July 2009 event, more than 9.67Tg dust were emitted from the study area and the maximum simulated dust emission rate is 540 (μgm−2 s−1). The west of Iraq, east of Syria and northwest of Jordan (Al-Nafud desert and western Euphrates alluvial plain) are found to be the most active areas of dust emission, contributing much to the dust emission from the Middle East region. In this study, more that 60% of dust particles were emitted from these areas and less than 10% were emitted from Iran dust sources. About 21% of the deposited dust was deposited in Iran land, while 79% in other parts of the study area. The dust load in the study area was estimated to be more than 0.3gm−2. The residence time of dust in the atmosphere was 6.2days over the study area, 7.8days over Iran and 6days over other parts. The simulation results exhibit that Iran contribution in emission rate in the study area is much lower than its contribution in dust deposition and residence time and the conclusion of this study can demonstrate the necessity of forming cooperation for suppressing the severe dust events.

      PubDate: 2017-01-16T04:41:38Z
      DOI: 10.1016/j.aeolia.2016.12.004
      Issue No: Vol. 24 (2017)
       
  • Assessment of dust activity and dust-plume pathways over Jazmurian Basin,
           southeast Iran
    • Authors: A. Rashki; M. Arjmand; D.G. Kaskaoutis
      Pages: 145 - 160
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): A. Rashki, M. Arjmand, D.G. Kaskaoutis
      Jazmurian (or hamun-e Jaz Murian) is a dried lake located in a topographic-low basin in southeast Iran and a major source for high dust emissions under favorable weather conditions. This work examines for the first time the dust activity over the basin by classifying the dust events (DEs, visibility <10km) and dust-storm events (DSEs, visibility <1km) based on observations at five local meteorological stations during the period 1990–2013. Analysis of the temporal evolution, seasonality, frequency and persistence (duration) of the DEs and DSEs, along with examination of the backward and forward air-mass trajectories in the Jazmurian Basin are the main objectives of the present study. The DEs exhibit maximum frequency in June–July and lowest in autumn and winter, while the DSEs peak mostly during March–May also presenting large variability between the stations. The frequency of both the DEs and DSEs increases during ∼2001–2004 due to a prolonged drought over southeastern Iran, while no significant tendency is found during the period 1990–2013. Further, the DEs and DSEs exhibit a clear diurnal pattern with highest frequency between 15:30 and 18:30 LST due to thermal convection and transported dust plumes. The analysis reveals an average frequency of 12.7 dust-storm days per year, while the DSEs last for 5.1h, on average, during the dust-storm days. The dust storms originating from Jazmurian affect mostly the northern coast of the Arabian Sea (Makran mountains), the Oman Sea, the southeastern Arabian Peninsula and the western Pakistan, while air masses from the arid/desert areas of central-eastern Iran and Arabia seem to further aggravate the dust-aerosol loading over Jazmurian.

      PubDate: 2017-01-30T10:57:34Z
      DOI: 10.1016/j.aeolia.2017.01.002
      Issue No: Vol. 24 (2017)
       
  • Terrestrial subaqueous seafloor dunes: Possible analogs for Venus
    • Authors: Lynn D.V. Neakrase; Martina Klose; Timothy N. Titus
      Abstract: Publication date: Available online 5 April 2017
      Source:Aeolian Research
      Author(s): Lynn D.V. Neakrase, Martina Klose, Timothy N. Titus
      Dunes on Venus, first discovered with Magellan Synthetic Aperture Radar (SAR) in the early 1990s, have fueled discussions about the viability of Venusian dunes and aeolian grain transport. Confined to two locations on Venus, the existence of the interpreted dunes provides evidence that there could be transportable material being mobilized into aeolian bedforms at the surface. However, because of the high-pressure high-temperature surface conditions, laboratory analog studies are difficult to conduct and results are difficult to extrapolate to full-sized, aeolian bedforms. Field sites of desert dunes, which are well-studied on Earth and Mars, are not analogous to what is observed on Venus because of the differences in the fluid environments. One potentially underexplored possibility in planetary science for Venus-analog dune fields could be subaqueous, seafloor dune fields on Earth. Known to the marine geology communities since the early 1960s, seafloor dunes are rarely cited in planetary aeolian bedform literature, but could provide a necessary thick-atmosphere extension to the classically studied aeolian dune environment literature for thinner atmospheres. Through discussion of the similarity of the two environments, and examples of dunes and ripples cited in marine literature, we provide evidence that subaqueous seafloor dunes could serve as analogs for dunes on Venus. Furthermore, the evidence presented here demonstrates the usefulness of the marine literature for thick-atmosphere planetary environments and potentially for upcoming habitable worlds and oceanic environment research program opportunities. Such useful cross-disciplinary discussion of dune environments is applicable to many planetary environments (Earth, Mars, Venus, Titan, etc.) and potential future missions.

      PubDate: 2017-04-11T11:50:50Z
      DOI: 10.1016/j.aeolia.2017.03.002
       
  • Leonard Horner and an enthusiasm for Loess
    • Authors: Ian Smalley; Holger Kels
      Abstract: Publication date: Available online 5 April 2017
      Source:Aeolian Research
      Author(s): Ian Smalley, Holger Kels
      Leonard Horner (1785–1864) made substantial contributions to the study of loess. He made field trips with J.J. Noeggerath and Charles Lyell and published useful material on the loess near Bonn. He was an unappreciated pioneer- he was the first person to direct attention to loess as a material. He pointed out that loess was intrinsically interesting. He studied the material transported by the Rhine, and the alluvial deposits in Egypt, looking for links to loess, and the problem of loess formation. He was born in Edinburgh in 1785 and directed the thoughts of young Charles Darwin towards science when he came to Edinburgh to study medicine. Circumstances placed him in Bonn in the critical years 1831–1833; in this time Charles Lyell married his eldest daughter Mary; and both Lyell and Horner encountered the loess. Lyell made it well known via vol.3 of the Principles of Geology, Horner became a loess enthusiast. In the summer of 1833 Horner & Lyell were in the crater of the Roderberg considering the more than 20m of loess deposited there. His major paper was published in 1836 (reporting the Roderberg excursion) and he joined Lyell’s list of loess investigators in the 5th edition of the Principles published in 1837. He was the last to join that select eleven: Bronn, Leonhard, Boue, Voltz, Steininger, Merian, Rozet, Hibbert, Noeggerath, von Meyer, Horner. Most of these were writing on the geology and landscapes of the Rhine valley, but Horner was drawing attention to the amazing nature of the loess itself, in particular the spectacular disaggregation on contact with water. He also published the first geological map of the Bonn region, including the Roderberg and the Siebengebirge, a region of loess and volcanoes.

      PubDate: 2017-04-11T11:50:50Z
      DOI: 10.1016/j.aeolia.2017.03.004
       
  • Development of large nebkhas along an accreting macrotidal coastline,
           Northern France
    • Authors: Marie-Hélène Ruz; Arnaud Héquette; Denis Marin
      Pages: 1 - 14
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Marie-Hélène Ruz, Arnaud Héquette, Denis Marin
      Very large isolated nebkhas, up to 4m high and 14m wide, have developed on the upper beach of a several hundred meters wide foreshore on the French coast of the Dover Strait. This macrotidal shoreline is characterized by abundant sediment supply from the shoreface related to the onshore welding of a nearshore sand bank. Continuing beach accretion provided the conditions for rapid seaward development of incipient foredunes. The nebkhas developed on the uppermost beach, slightly above the highest astronomical tide limit, forming hemispheric to oval-shaped mounds only reached by spring tides and/or storm surges. They do not form an incipient foredune zone, but mounds that grew vertically and remained in the form of isolated huge nebkhas disconnected from the incipient foredune zone by a swale. The nebkhas consist of scattered landforms that do not impede aeolian accretion landward in the incipient foredune zone where the maximum accretion rates were recorded. The distribution of such large coastal nebkhas is probably limited in beach environments since the descriptions of similar examples of aeolian coastal landforms are virtually absent in the scientific literature, suggesting that they are presumably restricted to low gradient macrotidal beaches associated with an excess of sand supply.
      Graphical abstract image

      PubDate: 2016-12-13T10:21:05Z
      DOI: 10.1016/j.aeolia.2016.11.002
      Issue No: Vol. 24 (2016)
       
  • Dust emission and transport over Iraq associated with the summer Shamal
           winds
    • Authors: D. Bou Karam Francis; C. Flamant; J.-P. Chaboureau; J. Banks; J. Cuesta; H. Brindley; L. Oolman
      Pages: 15 - 31
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): D. Bou Karam Francis, C. Flamant, J.-P. Chaboureau, J. Banks, J. Cuesta, H. Brindley, L. Oolman
      In this study, we investigate the diurnal evolution of the summer Shamal wind (a quasi-permanent low-level northwesterly wind feature) and its role in dust emission and transport over Iraq, using ground-based and space-borne observations together with a numerical simulation performed with the mesoscale model meso-NH. A 6-year dataset from the synoptic stations over Iraq allows establishing the prominence of the link between strong near surface winds and reduced visibility in the summer. The detailed processes at play during Shamal events are explored on the basis of a meso-NH simulation for a given, representative case study (25 June–3 July 2010). The Shamal exhibits an out-of-phase relationship between the surface wind and winds in the lower troposphere (typically 500m above ground level), the maximum surface wind speeds being observed during the day while in altitude the maximum wind speeds are observed at night. The daytime near surface winds, at the origin of dust emission, are associated with the downward transfer of momentum from the nocturnal low-level jet to the surface due to turbulent mixing after solar heating commences each day. For the first time, an estimate of the dust load associated with summer Shamal events over Iraq has been made using aerosol optical depths derived from the Spinning Enhanced Visible and Infrared Imager, the Moderate Resolution Imaging Spectroradiometer, and the simulation. The dust load exhibits a large diurnal variability, with a daily minimum value of 1Tg around 0600UTC and a daily peak of 2.5Tg or more around 1500UTC, and is driven by the diurnal cycle of the near surface wind speed. The daily dust load peak associated with the summer Shamal over Iraq is in the same order of magnitude as those derived from simulations downstream of the Bodélé depression in Chad, known to be the world’s largest dust source.

      PubDate: 2016-12-13T10:21:05Z
      DOI: 10.1016/j.aeolia.2016.11.001
      Issue No: Vol. 24 (2016)
       
  • Abrasion resistance of muscovite in aeolian and subaqueous transport
           experiments
    • Authors: Calvin J. Anderson; Alexander Struble; John H. Whitmore
      Pages: 33 - 37
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Calvin J. Anderson, Alexander Struble, John H. Whitmore
      Complementary aeolian and subaqueous transport experiments showed a trend in muscovite abrasion that may be useful for identifying ancient sandstones as aeolian or subaqueous in origin. We found that our experimental aeolian processes pulverized the micas quickly, while our subaqueous processes did not. In a pair of abrasion resistance experiments conducted with micaceous quartz sand, it was found that large muscovite grains were (1) reduced by aeolian processes to less than 500μm in just 4days, and (2) preserved by subaqueous processes to 610±90μm even after 356days. At 20days of aeolian transport no loose micas could be found even under the microscope, but after a year of subaqueous transport loose muscovite grains could still be seen with the naked eye. Thus, the occurrence and character of micas in a sandstone, particularly muscovite, may be helpful in determining the ancient depositional process.

      PubDate: 2016-12-21T10:27:31Z
      DOI: 10.1016/j.aeolia.2016.11.003
      Issue No: Vol. 24 (2016)
       
  • An Israeli haboob: Sea breeze activating local anthropogenic dust sources
           in the Negev loess
    • Authors: Onn Crouvi; Uri Dayan; Rivka Amit; Yehouda Enzel
      Pages: 39 - 52
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Onn Crouvi, Uri Dayan, Rivka Amit, Yehouda Enzel
      Meso-scale weather systems, such as convective haboobs, are considered to be an important dust generation mechanism. In Israel, however, rather than of meso-scale weather systems, most dust storms are generated by synoptic-scale systems, originating from Sahara and Arabia. Consequently, only distal sources of suspended and deposited dust in Israel are currently reported. Here we report the first detailed study on the merging of synoptic- and meso-scale weather systems leading to a prominent dust outbreak over the Negev, Israel. During the afternoon of May 2nd, 2007, a massive dust storm covered the northern Negev, forming a one kilometer high wall of dust. The haboob was associated with PM10 concentrations of 1000–1500μgm−3 that advanced at a speed of 10–15ms−1 and caused temporary closure of local airports. In contrast to most reported haboobs, this one was generated by a sea breeze front acting as a weak cold front enhanced by a cold core cyclone positioned over Libya and Egypt. The sea breeze that brought cold and moist marine air acted as a gravity current with strong surface winds. The sources for the haboob were the loessial soils of the northwestern Negev, especially agricultural fields that were highly disturbed in late spring to early summer. Such surface disturbance is caused by agricultural and/or intensive grazing practices. Our study emphasizes the importance of local dust sources in the Negev and stresses loess recycling as an important process in contemporary dust storms over Israel.
      Graphical abstract image

      PubDate: 2016-12-21T10:27:31Z
      DOI: 10.1016/j.aeolia.2016.12.002
      Issue No: Vol. 24 (2016)
       
  • Desert dust hazards: A global review
    • Authors: N.J. Middleton
      Pages: 53 - 63
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): N.J. Middleton
      Dust storms originate in many of the world’s drylands and frequently present hazards to human society, both within the drylands themselves but also outside drylands due to long-range transport of aeolian sediments. Major sources of desert dust include the Sahara, the Middle East, central and eastern Asia, and parts of Australia, but dust-raising occurs all across the global drylands and, on occasion, beyond. Dust storms occur throughout the year and they vary in frequency and intensity over a number of timescales. Long-range transport of desert dust typically takes place along seasonal transport paths. Desert dust hazards are here reviewed according to the three phases of the wind erosion system: where dust is entrained, during the transport phase, and on deposition. This paper presents a synthesis of these hazards. It draws on empirical examples in physical geography, medical geology and geomorphology to discuss case studies from all over the world and in various fields. These include accelerated soil erosion in agricultural zones – where dust storms represent a severe form of accelerated soil erosion – the health effects of air pollution caused by desert aerosols via their physical, chemical and biological properties, transport accidents caused by poor visibility during desert dust events, and impacts on electricity generation and distribution. Given the importance of desert dust as a hazard to human societies, it is surprising to note that there have been relatively few attempts to assess their impact in economic terms. Existing studies in this regard are also reviewed, but the wide range of impacts discussed in this paper indicates that desert dust storms deserve more attention in this respect.

      PubDate: 2016-12-28T10:32:28Z
      DOI: 10.1016/j.aeolia.2016.12.001
      Issue No: Vol. 24 (2016)
       
  • Analysis of an optical gate device for measuring aeolian sand movement
    • Authors: V. Etyemezian; G. Nikolich; W. Nickling; J.S. King; J.A. Gillies
      Pages: 65 - 79
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): V. Etyemezian, G. Nikolich, W. Nickling, J.S. King, J.A. Gillies
      Movement of sand in response to wind is the most important feature of aeolian sediment transport on Earth and other planets. Through sand blasting during saltation, large amounts of dust are ejected into the atmosphere and transported long distances, impacting climate and human health. Despite continuing improvements, currently available devices for field measurement of sand movement have limitations. An optical gate device (OGD) for detecting the movement, size, and possibly speed of individual sand grains during aeolian sediment transport was analyzed. The approach uses the highly time resolved signal from these sensors, which consist of a light emitter and a photosensitive sensor. A specific OGD that is manufactured by Optek (Carrollton, Texas, USA) was tested in a sediment transport wind tunnel alongside trap-style devices. The OGD device provided particle counts and total signal response that were well correlated with sand trap data (R2 between 0.66 and 0.88). Inter-comparison among eight identical units of the OGD showed excellent repeatability (R2 >0.98 for 7 of 8 units). Subsequent tests revealed that the response of the phototransistor (light sensor) can be linear when operated within certain workable limits. Practical implications of this are that there is potential for extracting size distribution information. Limits imposed by noise levels in the signal and interferences from extraneous light sources were also identified. Despite the results presented being specific to the OGD model tested, much of the approach outlined is applicable to any OGD-type device (including Wenglor®) if the signal of the photo detector can be accessed directly.

      PubDate: 2016-12-28T10:32:28Z
      DOI: 10.1016/j.aeolia.2016.11.005
      Issue No: Vol. 24 (2016)
       
  • The characterization of haboobs and the deposition of dust in Tempe, AZ
           from 2005 to 2014
    • Authors: Jershon Dale Eagar; Pierre Herckes; Hilairy Ellen Hartnett
      Pages: 81 - 91
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Jershon Dale Eagar, Pierre Herckes, Hilairy Ellen Hartnett
      Dust storms known as ‘haboobs’ occur in Tempe, AZ during the North American monsoon season. This work presents a catalog of haboob occurrence over the time period 2005–2014. A classification method based on meteorological and air quality measurements is described. The major factors that distinguish haboobs events from other dust events and from background conditions are event minimum visibility, maximum wind or gust speed, and maximum PM10 (particulate matter with aerodynamic diameters of 10μm or less) concentration. We identified from 3 to 20 haboob events per year over the period from 2005 to 2014. The calculated annual TSP (total suspended particulate) dry deposition ranged from a low of 259kgha−1 in 2010 to a high of 2950kgha−1 in 2011 with a mean of 950kgha−1 yr−1. The deposition of large particles (PM>10) is greater than the deposition of PM10. The TSP dry deposition during haboobs is estimated to contribute 74% of the total particulate mass deposited in Tempe.
      Graphical abstract image

      PubDate: 2016-12-28T10:32:28Z
      DOI: 10.1016/j.aeolia.2016.11.004
      Issue No: Vol. 24 (2016)
       
  • The formation of snow streamers in the turbulent atmosphere boundary layer
    • Authors: Ning Huang; Zheng-Shi Wang
      Pages: 1 - 10
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): Ning Huang, Zheng-Shi Wang
      The drifting snow in the turbulent atmosphere boundary layer is an important type of aeolian multi-phase flow. Current theoretical and numerical studies of drifting snow mostly consider the flow field as steady wind velocity. Whereas, little is known about the effects of turbulent wind structures on saltating snow particles. In this paper, a 3-D drifting snow model based on Large Eddy Simulation is established, in which the trajectory of every snow grain is calculated and the coupling effect between wind field and snow particles is considered. The results indicate that the saltating snow particles are re-organized by the suction effect of high-speed rotating vortexes, which results in the local convergence of particle concentration, known as snow streamers. The turbulent wind leads to the spatial non-uniform of snow particles lifted by aerodynamic entrainment, but this does not affect the formation of snow streamers. Whereas the stochastic grain-bed interactions make a great contribution to the final shapes of snow streamers. Generally, snow streamers display a characteristic length about 0.5m and a characteristic width of approximately 0.16m, and their characteristic sizes are not sensitive to the wind speed. Compared to the typical sand streamer, snow streamer is slightly narrower and the occurrence of other complex streamer patterns is later than that of sand streamers due to the better follow performance of snow grains with air flow.

      PubDate: 2016-10-04T17:22:19Z
      DOI: 10.1016/j.aeolia.2016.09.002
      Issue No: Vol. 23 (2016)
       
  • Evolving flux of Asian dust in the North Pacific Ocean since the late
           Oligocene
    • Authors: Wenfang Zhang; Jun Chen; Junfeng Ji; Gaojun Li
      Pages: 11 - 20
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): Wenfang Zhang, Jun Chen, Junfeng Ji, Gaojun Li
      The aeolian deposits in the North Pacific Ocean (NPO) serve as important archives for the surface processes in the arid Asian interior. Aeolian flux, which is usually based on the ‘operationally defined aeolian dust’ (ODED) extracted from the pelagic sediments, is a widely used paleo-proxy that reflects aridity of the source regions. However, such reconstruction of aeolian flux is subject to large uncertainty associated with the age model due to the low sedimentation rate and lack of calcareous nannofossil of the pelagic sediments. Precipitation of authigenic minerals and contribution of volcanic ash also complicate interpretation of the reconstructed ODED flux. This work extracts ODED from the sediments recovered at Ocean Drilling Program (ODP) site 1208 on the Shatsky Rise in NPO. The high sedimentation rate at ODP site 1208 enables a high-resolution age model. The resulting ODED flux, which shows a progressive increasing trend over the past 25Ma, is very different from the previous reconstructions. The study indicates that authigenic phillipsite contribute a significant portion to the sediment of 25–18Ma, but the relative contribution of Asian dust to the ODED is roughly constant (60–80%) over the past 18Ma. Thus, the progressive increasing trend of ODED flux at the ODP site 1208 is not contributed by authigenic phillipsite and volcanic ash but reflect the increasing flux of Asian dust. We propose that the increasing flux of Asian dust in NPO reflects the progressive aridification of Asian interior in response to global cooling and/or regional mountain building.

      PubDate: 2016-10-04T17:22:19Z
      DOI: 10.1016/j.aeolia.2016.09.004
      Issue No: Vol. 23 (2016)
       
  • Concentrations of mineral aerosol from desert to plains across the central
           Rocky Mountains, western United States
    • Authors: Richard L. Reynolds; Seth M. Munson; Daniel Fernandez; Harland L. Goldstein; Jason C. Neff
      Pages: 21 - 35
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): Richard L. Reynolds, Seth M. Munson, Daniel Fernandez, Harland L. Goldstein, Jason C. Neff
      Mineral dusts can have profound effects on climate, clouds, ecosystem processes, and human health. Because regional dust emission and deposition in western North America are not well understood, measurements of total suspended particulate (TSP) from 2011 to 2013 were made along a 500-km transect of five remote sites in Utah and Colorado, USA. The TSP concentrations in μgm−3 adjusted to a 24-h period were relatively high at the two westernmost, dryland sites at Canyonlands National Park (mean=135) and at Mesa Verde National Park (mean=99), as well as at the easternmost site on the Great Plains (mean=143). The TSP concentrations at the two intervening montane sites were less, with more loading on the western slope of the Rocky Mountains (Telluride, mean=68) closest to the desert sites compared with the site on the eastern slope (Niwot Ridge, mean=58). Dust concentrations were commonly highest during late winter-late spring, when Pacific frontal storms are the dominant causes of regional wind. Low concentrations (<7wt%) of organic matter indicated that rock-derived mineral particles composed most TSP. Most TSP mass was carried by particle sizes larger than 10μm (PM>10), as revealed by relatively low average daily concentrations of fine (<5μgm−3; PM2.5) and coarse (<10μgm−3; PM2.5–10) fractions monitored at or near four sites. Standard air-quality measurements for PM2.5 andPM10 apparently do not capture the large majority of mineral-particulate pollution in the remote western interior U.S.
      Graphical abstract image

      PubDate: 2016-10-04T17:22:19Z
      DOI: 10.1016/j.aeolia.2016.09.001
      Issue No: Vol. 23 (2016)
       
  • High-resolution dust modelling over complex terrains in West Asia
    • Authors: S. Basart; L. Vendrell; J.M. Baldasano
      Pages: 37 - 50
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): S. Basart, L. Vendrell, J.M. Baldasano
      The present work demonstrates the impact of model resolution in dust propagation in a complex terrain region such as West Asia. For this purpose, two simulations using the NMMB/BSC-Dust model are performed and analysed, one with a high horizontal resolution (at 0.03°×0.03°) and one with a lower horizontal resolution (at 0.33°×0.33°). Both model experiments cover two intense dust storms that occurred on 17–20 March 2012 as a consequence of strong northwesterly Shamal winds that spanned over thousands of kilometres in West Asia. The comparison with ground-based (surface weather stations and sunphotometers) and satellite aerosol observations (Aqua/MODIS and MSG/SEVIRI) shows that despite differences in the magnitude of the simulated dust concentrations, the model is able to reproduce these two dust outbreaks. Differences between both simulations on the dust spread rise on regional dust transport areas in south-western Saudi Arabia, Yemen and Oman. The complex orography in south-western Saudi Arabia, Yemen and Oman (with peaks higher than 3000m) has an impact on the transported dust concentration fields over mountain regions. Differences between both model configurations are mainly associated to the channelization of the dust flow through valleys and the differences in the modelled altitude of the mountains that alters the meteorology and blocks the dust fronts limiting the dust transport. These results demonstrate how the dust prediction in the vicinity of complex terrains improves using high-horizontal resolution simulations.

      PubDate: 2016-10-11T17:48:41Z
      DOI: 10.1016/j.aeolia.2016.09.005
      Issue No: Vol. 23 (2016)
       
  • Evaporative sodium salt crust development and its wind tunnel derived
           transport dynamics under variable climatic conditions
    • Authors: Joanna M. Nield; Cheryl McKenna Neuman; Patrick O’Brien; Robert G. Bryant; Giles F.S. Wiggs
      Pages: 51 - 62
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): Joanna M. Nield, Cheryl McKenna Neuman, Patrick O’Brien, Robert G. Bryant, Giles F.S. Wiggs
      Playas (or ephemeral lakes) can be significant sources of dust, but they are typically covered by salt crusts of variable mineralogy and these introduce uncertainty into dust emission predictions. Despite the importance of crust mineralogy to emission potential, little is known about (i) the effect of short-term changes in temperature and relative humidity on the erodibility of these crusts, and (ii) the influence of crust degradation and mineralogy on wind speed threshold for dust emission. Our understanding of systems where emission is not driven by impacts from saltators is particularly poor. This paper describes a wind tunnel study in which dust emission in the absence of saltating particles was measured for a suite of climatic conditions and salt crust types commonly found on Sua Pan, Botswana. The crusts were found to be non-emissive under climate conditions characteristic of dawn and early morning, as compared to hot and dry daytime conditions when the wind speed threshold for dust emission appears to be highly variable, depending upon salt crust physicochemistry. Significantly, sodium sulphate rich crusts were found to be more emissive than crusts formed from sodium chloride, while degraded versions of both crusts had a lower emission threshold than fresh, continuous crusts. The results from this study are in agreement with in-situ field measurements and confirm that dust emission from salt crusted surfaces can occur without saltation, although the vertical fluxes are orders of magnitude lower (∼10μg/m/s) than for aeolian systems where entrainment is driven by particle impact.

      PubDate: 2016-10-11T17:48:41Z
      DOI: 10.1016/j.aeolia.2016.09.003
      Issue No: Vol. 23 (2016)
       
  • Using albedo to reform wind erosion modelling, mapping and monitoring
    • Authors: Adrian Chappell; Nicholas P. Webb
      Pages: 63 - 78
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): Adrian Chappell, Nicholas P. Webb
      Wind erosion and dust emission models are used to assess the impacts of dust on radiative forcing in the atmosphere, cloud formation, nutrient fertilisation and human health. The models are underpinned by a two-dimensional geometric property (lateral cover; L) used to characterise the three-dimensional aerodynamic roughness (sheltered area or wakes) of the Earth’s surface and calibrate the momentum it extracts from the wind. We reveal a fundamental weakness in L and demonstrate that values are an order of magnitude too small and significant aerodynamic interactions between roughness elements and their sheltered areas have been omitted, particularly under sparse surface roughness. We describe a solution which develops published work to establish a relation between sheltered area and the proportion of shadow over a given area; the inverse of direct beam directional hemispherical reflectance (black sky albedo; BSA). We show direct relations between shadow and wind tunnel measurements and thereby provide direct calibrations of key aerodynamic properties. Estimation of the aerodynamic parameters from albedo enables wind erosion assessments over areas, across platforms from the field to airborne and readily available satellite data. Our new approach demonstrated redundancy in existing wind erosion models and thereby reduced model complexity and improved fidelity. We found that the use of albedo enabled an adequate description of aerodynamic sheltering to characterise fluid dynamics and predict sediment transport without the use of a drag partition scheme (Rt ) or threshold friction velocity (u∗t ). We applied the calibrations to produce global maps of aerodynamic properties which showed very similar spatial patterns to each other and confirmed the redundancy in the traditional parameters of wind erosion modelling. We evaluated temporal patterns of predicted horizontal mass flux at locations across Australia which revealed variation between land cover types that would not be detected using traditional models. Our new approach provided new opportunities to investigate the dynamics of wind erosion in space and time and elucidate aeolian processes across scales.

      PubDate: 2016-10-16T18:41:57Z
      DOI: 10.1016/j.aeolia.2016.09.006
      Issue No: Vol. 23 (2016)
       
  • Windblown sand saltation: A statistical approach to fluid threshold shear
           velocity
    • Authors: Lorenzo Raffaele; Luca Bruno; Franco Pellerey; Luigi Preziosi
      Pages: 79 - 91
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): Lorenzo Raffaele, Luca Bruno, Franco Pellerey, Luigi Preziosi
      The reliable prediction in probabilistic terms of the consequences of aeolian events related to sand transport phenomena is a key element for human activities in arid regions. Threshold shear velocity generating sand lifting is a key component of such a prediction. It suffers from the effect of uncertainties of different origin, such as those related to the physical phenomena, measurement procedures, and modelling. Semi empirical models are often fitted to a small amount of data, while recent probabilistic models needs the probability distribution of several random variables. Triggered by this motivation, this paper proposes a purely statistical approach to fluid threshold shear velocity for sand saltation, treated as a single comprehensive random variable. A data set is derived from previously published studies. Estimates of conditional probability distributions of threshold shear velocity for given grain diameters are given. The obtained statistical moments are critically compared to some deterministic semi empirical models refitted to the same collected data. The proposed statistical approach allows to obtain high order statistics useful for practical purposes.

      PubDate: 2016-10-16T18:41:57Z
      DOI: 10.1016/j.aeolia.2016.10.002
      Issue No: Vol. 23 (2016)
       
  • Increasing dust fluxes on the northeastern Tibetan Plateau linked with the
           Little Ice Age and recent human activity since the 1950s
    • Authors: Dejun Wan; Zhangdong Jin; Fei Zhang; Lei Song; Jinsong Yang
      Pages: 93 - 102
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): Dejun Wan, Zhangdong Jin, Fei Zhang, Lei Song, Jinsong Yang
      Arid and semi-arid areas in inner Asia contribute lots of mineral dust in the northern hemisphere, but dust flux evolution in the past is poorly constrained. Based on particle sizes and elemental compositions of a sediment core from Lake Qinghai on the northeastern Tibetan Plateau, dust fluxes during ∼1518–2011 A.D. were reconstructed based on 18–100μm fractions of the lake sediment. The dust fluxes during the past ∼500years ranged between 100 and 300g/m2/yr, averaging 202g/m2/yr, experiencing four stages: Stage 1 (∼1518–1590s), the flux was averaged 165g/m2/yr, much lower than that in the Stage 2 (1590s–1730s, 254g/m2/yr); similarly, an average flux of 169g/m2/yr in the Stage 3 (1730s–1950s) was followed by an increased flux of 259g/m2/yr in the Stage 4 (1950s–2011). During the first three stages the fluxes were dominated by natural dust activities in arid inner Asia, having a positive relation with wind intensity but a poor correlation with effective moisture (or precipitation) and temperature. The high dust flux in Stage 2 was due to relatively strong wind during the maximum Little Ice Age, whereas the remarkably high flux in 1950s–2011 was resulted from recent increasing human activities in northwestern China. The dust record not only documents past dust fluxes on the northeastern Tibetan Plateau but also reflects evolutions and mechanisms of dust activity/emission in inner Asia during the past ∼500years.

      PubDate: 2016-11-01T23:11:16Z
      DOI: 10.1016/j.aeolia.2016.10.003
      Issue No: Vol. 23 (2016)
       
  • Seasonal geomorphic processes and rates of sand movement at Mount Baldy
           dune in Indiana, USA
    • Authors: Zoran Kilibarda; Vesna Kilibarda
      Pages: 103 - 114
      Abstract: Publication date: December 2016
      Source:Aeolian Research, Volume 23, Part A
      Author(s): Zoran Kilibarda, Vesna Kilibarda
      Winds are very strong, frequent, and have high energy (annual DP ∼800 VU) along the southern shores of Lake Michigan, allowing the coexistence of fixed and active dunes. Six years (2007–13) of monitoring Mount Baldy in the Indiana Dunes National Lakeshore reveals that this is the most active coastal dune in the Great Lakes region. This paper documents aeolian processes and changes in the dune’s morphology that occur temporarily, following storms, or seasonally, due to weather (climate) variations. Most of the sand transport in this area takes place during strong storms with gale force (>17.5m/s) winds, which occur in the autumn and winter months. A single storm, such as the October 28–31, 2013 event, can contribute 25% of the annual sand transport and dune movement inland. In its most active year (June 1, 2011 through May 31, 2012), Mount Baldy moved inland on average 4.34m, with a maximum of 6.52m along the blowout’s axis (155° azimuth). During this particularly active season, there were six storms with sustained gale force winds, winter air temperatures were warmer than average, and shelf ice on Lake Michigan lasted only one day. The dune is least active during the summer season, when the winds are weakest. The late fall and winter winds are the strongest. But in a typical year, most of the dune’s advance inland takes place during the spring thaw when sand is released from over-steepened and lumpy slip face, allowing it to avalanche to the toe of the slip face. However, with a warming air temperatures, a reduction in the duration of winter shelf ice, and rising Lake Michigan levels, the annual rates of sand transport and dune movement may increase. The recent Mount Baldy management strategy, which includes planting vegetation and installing wind barriers on the dune’s stoss side in an effort to fix the dune and stop its further movement inland, may potentially cause the destruction of the mobile sand, open dune habitat, resulting in the extinction of rare plants, insects, lizards, birds, and mammals.
      Graphical abstract image

      PubDate: 2016-11-15T13:28:00Z
      DOI: 10.1016/j.aeolia.2016.10.004
      Issue No: Vol. 23 (2016)
       
  • Saharan dust deposition in the Carpathian Basin and its possible effects
           on interglacial soil formation
    • Authors: György Varga; Csaba Cserháti; János Kovács; Zoltán Szalai
      Pages: 1 - 12
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): György Varga, Csaba Cserháti, János Kovács, Zoltán Szalai
      Several hundred tons of windblown dust material are lifted into the atmosphere and are transported every year from Saharan dust source areas towards Europe having an important climatic and other environmental effect also on distant areas. According to the systematic observations of modern Saharan dust events, it can be stated that dust deflated from North African source areas is a significant constituent of the atmosphere of the Carpathian Basin and Saharan dust deposition events are identifiable several times in a year. Dust episodes are connected to distinct meteorological situations, which are also the determining factors of the different kinds of depositional mechanisms. By using the adjusted values of dust deposition simulations of numerical models, the annual Saharan dust flux can be set into the range of 3.2–5.4g/m2/y. Based on the results of past mass accumulation rates calculated from stratigraphic and sedimentary data of loess–paleosol sequences, the relative contribution of Saharan dust to interglacial paleosol material was quantified. According to these calculations, North African exotic dust material can represent 20–30% of clay and fine silt-sized soil components of interglacial paleosols in the Carpathian Basin. The syngenetic contribution of external aeolian dust material is capable to modify physicochemical properties of soils and hereby the paleoclimatic interpretation of these pedogene stratigraphic units.

      PubDate: 2016-06-16T18:04:24Z
      DOI: 10.1016/j.aeolia.2016.05.004
      Issue No: Vol. 22 (2016)
       
  • Airflow and sediment movement within an inland blowout in Hulun Buir sandy
           grassland, Inner Mongolia, China
    • Authors: Yu Sun; Eerdun Hasi; Meiping Liu; Huishi Du; Chao Guan; Binbin Tao
      Pages: 13 - 22
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Yu Sun, Eerdun Hasi, Meiping Liu, Huishi Du, Chao Guan, Binbin Tao
      We measured wind flows and sediment transport rates through a blowout in Hulun Buir grassland, Inner Mongolia. Topography and the angle of incidence between the approaching wind and the blowout long-axis significantly affected the air flow. Flow separated and decelerated at the western wall and accelerated towards the east, until maximum wind speed occurred at the top of the depositional lobe, and then decelerated on the lee side. When airflow emerged on the eastern wall, resultant directions were always NW. When winds approached from directions within 17.5° of the blowout axis, both the northwestern and southwestern walls developed turbulent flow, and significant topographic steering occurred. The deceleration zone expanded eastwards from 10.3 to 12.8m from the western rim. When the wind direction was more oblique than 17.5°, turbulent flow at the southwestern wall disappeared. ‘S-shaped’ flow intensified, causing more pronounced steering at the bottom, but topographic steering elsewhere was reduced, and the boundary of the deceleration moved to 10m from the western rim. Minor sediment deposition occurred on the western wall, while other parts were eroded; maximum sediment transport occurred at the top of the depositional lobe. The approaching wind speed affected the sediment transport rate more than the direction; and spatial variability in sediment transport reflected differences in compaction, vegetation coverage, slope, aspect, and upwind sediment availability, resulting in asymmetrical development. Overall, flow-form interactions governed the flow structures and controlled the evolution of the blowout via sediment transport.

      PubDate: 2016-06-16T18:04:24Z
      DOI: 10.1016/j.aeolia.2016.05.002
      Issue No: Vol. 22 (2016)
       
  • The National Wind Erosion Research Network: Building a standardized
           long-term data resource for aeolian research, modeling and land management
           
    • Authors: Nicholas P. Webb; Jeffrey E. Herrick; Justin W. Van Zee; Ericha M. Courtright; Christopher H. Hugenholtz; Ted M. Zobeck; Gregory S. Okin; Thomas E. Barchyn; Benjamin J. Billings; Robert Boyd; Scott D. Clingan; Brad F. Cooper; Michael C. Duniway; Justin D. Derner; Fred A. Fox; Kris M. Havstad; Philip Heilman; Valerie LaPlante; Noel A. Ludwig; Loretta J. Metz; Mark A. Nearing; M. Lee Norfleet; Frederick B. Pierson; Matt A. Sanderson; Brenton S. Sharratt; Jean L. Steiner; John Tatarko; Negussie H. Tedela; David Toledo; Robert S. Unnasch; R. Scott Van Pelt; Larry Wagner
      Pages: 23 - 36
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Nicholas P. Webb, Jeffrey E. Herrick, Justin W. Van Zee, Ericha M. Courtright, Christopher H. Hugenholtz, Ted M. Zobeck, Gregory S. Okin, Thomas E. Barchyn, Benjamin J. Billings, Robert Boyd, Scott D. Clingan, Brad F. Cooper, Michael C. Duniway, Justin D. Derner, Fred A. Fox, Kris M. Havstad, Philip Heilman, Valerie LaPlante, Noel A. Ludwig, Loretta J. Metz, Mark A. Nearing, M. Lee Norfleet, Frederick B. Pierson, Matt A. Sanderson, Brenton S. Sharratt, Jean L. Steiner, John Tatarko, Negussie H. Tedela, David Toledo, Robert S. Unnasch, R. Scott Van Pelt, Larry Wagner
      The National Wind Erosion Research Network was established in 2014 as a collaborative effort led by the United States Department of Agriculture’s Agricultural Research Service and Natural Resources Conservation Service, and the United States Department of the Interior’s Bureau of Land Management, to address the need for a long-term research program to meet critical challenges in wind erosion research and management in the United States. The Network has three aims: (1) provide data to support understanding of basic aeolian processes across land use types, land cover types, and management practices, (2) support development and application of models to assess wind erosion and dust emission and their impacts on human and environmental systems, and (3) encourage collaboration among the aeolian research community and resource managers for the transfer of wind erosion technologies. The Network currently consists of thirteen intensively instrumented sites providing measurements of aeolian sediment transport rates, meteorological conditions, and soil and vegetation properties that influence wind erosion. Network sites are located across rangelands, croplands, and deserts of the western US. In support of Network activities, http://winderosionnetwork.org was developed as a portal for information about the Network, providing site descriptions, measurement protocols, and data visualization tools to facilitate collaboration with scientists and managers interested in the Network and accessing Network products. The Network provides a mechanism for engaging national and international partners in a wind erosion research program that addresses the need for improved understanding and prediction of aeolian processes across complex and diverse land use types and management practices.

      PubDate: 2016-06-16T18:04:24Z
      DOI: 10.1016/j.aeolia.2016.05.005
      Issue No: Vol. 22 (2016)
       
  • Experimental and numerical study of Sharp’s shadow zone hypothesis
           on sand ripple wavelength
    • Authors: Erez Schmerler; Itzhak Katra; Jasper F. Kok; Haim Tsoar; Hezi Yizhaq
      Pages: 37 - 46
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Erez Schmerler, Itzhak Katra, Jasper F. Kok, Haim Tsoar, Hezi Yizhaq
      Despite advances in understanding processes of sand transport by saltation and reptation, which are involved in the formation of sand ripples, the mechanisms that determine the linear dependence of ripple spacing on wind speed and their relative importance are yet unknown. In a pivotal study, Sharp (1963) proposed that this linear dependence arises from the scaling of the ripples’ shadow zone – the part of the ripple devoid of particle impacts – with the wind speed. Here, we test this hypothesis by integrating wind tunnel experiments with numerical simulations of saltation. Specifically, we measured the effective shadow zone by using sand traps designed for this purpose and found a linear relationship between the shadow zone and the wind shear velocity, consistent with Sharp’s hypothesis. However, contrary to what Sharp assumed, we found that the shadow zone is not completely screened from particle impacts, which as indicated by numerical simulations is due to the wide distribution of impact angles. Nonetheless, the shadow zone can be one of the major mechanisms contributing to the linear increase of the ripple wavelength with wind speed at the nonlinear growth stage of the ripples where merging events between small ripples take place. However, for the initial stage of ripple development, when the ripple dimension is small, other mechanisms can be dominant, such as the recently suggested resonant saltation trajectory (Durán et al., 2014).

      PubDate: 2016-06-16T18:04:24Z
      DOI: 10.1016/j.aeolia.2016.05.006
      Issue No: Vol. 22 (2016)
       
  • A numerical study on dust devils with implications to global dust budget
           estimates
    • Authors: Martina Klose; Yaping Shao
      Pages: 47 - 58
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Martina Klose, Yaping Shao
      The estimates of the contribution of dust devils (DDs) to the global dust budget have large uncertainties because the dust emission mechanisms in DDs are not yet well understood. In this study, a large-eddy simulation model coupled with a dust scheme is used to investigate DD dust entrainment. DDs are identified from the simulations using various threshold values for pressure drop and vorticity in the DD center. A vortex-tracking algorithm is presented, which automatically detects and tracks vortices based on different pressure drop and vorticity criteria. The results show that DD dust lifting can be largely explained by convective turbulent dust emission. DD dust entrainment varies strongly between individual DDs even for similar atmospheric conditions, but the maximum emissions are determined by atmospheric stability. By relating DD emission and counts to the Richardson number, we propose a new and simple method to estimate regional and global DD dust transport.

      PubDate: 2016-06-16T18:04:24Z
      DOI: 10.1016/j.aeolia.2016.05.003
      Issue No: Vol. 22 (2016)
       
  • The north-eastern aeolian ‘European Sand Belt’ as potential record of
           environmental changes: A case study from Eastern Latvia and Southern
           Estonia
    • Authors: Edyta Kalińska-Nartiša; Christine Thiel; Māris Nartišs; Jan-Pieter Buylaert; Andrew S. Murray
      Pages: 59 - 72
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Edyta Kalińska-Nartiša, Christine Thiel, Māris Nartišs, Jan-Pieter Buylaert, Andrew S. Murray
      The Latvian and Estonian inland dunes belong to the north-eastern part of the ‘European Sand Belt’ (ESB). These dunes are widely distributed over broad glaciolacustrine plains and Late Glacial alluvial deltas, considered to be potential sources for the aeolian material. Little is known about these aeolian sediments and their substratum; here we present a detailed sedimentary structural and textural characterisation together with a luminescence-based chronology. Through a comparison between grain-size, rounding of quartz grains and surface characteristics in medium/coarse (0.5–0.8mm) sand, and the light mineral content, we found an alternation of aeolian and periglacial components. Further, short-lasting aeolian abrasion and/or transportation periods, and a significant contribution of a nearby sediment source are suggested. Luminescence dating points to aeolian sand accumulation and dune formation between ∼16ka and ∼9ka. However, we also observed some presumably watertable controlled environmental conditions at ∼13ka; this corresponds with the occurrence of an ice-dammed/proglacial lake.

      PubDate: 2016-06-18T18:38:00Z
      DOI: 10.1016/j.aeolia.2016.06.002
      Issue No: Vol. 22 (2016)
       
  • A wind-tunnel study on saltation and PM10 emission from agricultural soils
    • Authors: Fernando Avecilla; Juan E. Panebianco; Daniel E. Buschiazzo
      Pages: 73 - 83
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Fernando Avecilla, Juan E. Panebianco, Daniel E. Buschiazzo
      PM10 emission depends on the texture and the aggregation state of a soil. A decisive but less studied factor is the saltation fraction of the soil (fraction between 100 and 500μm). Six soils of contrasting textures were selected, and a wind tunnel study was carried out under three different saltation conditions: increased saltation, in which a sample of the saltation fraction was added to the air stream prior to the soil bed; no saltation added, in which the soil bed eroded without the addition of extra saltation fraction; and only saltation, in which the saltation fraction was injected into the air stream in the absence of the soil bed. Results indicated that the saltation efficiency for PM10 emission increased with the fine fraction content of the soil and decreased with the sand content, but this process showed a complex behavior depending on the cohesion and stability of the aggregates. An index for describing the saltation efficiency of the studied soils was proposed based on the combination of three parameters: the PM10 content, the amount of saltation fraction available in the soil surface, and an aggregation parameter (clay × organic matter content). Increasing the saltation rate increased the PM10 emission from the eroding soil bed, except for the sandy soil. Results suggest that the main mechanisms of PM10 emission under saltation conditions differ according to the soil texture: detachment of the PM10 adhered to the grains of sand predominates on sandy soils and fragmentation on finer soils, but both processes occur together on high-emitting soils of intermediate textures.

      PubDate: 2016-07-01T17:01:15Z
      DOI: 10.1016/j.aeolia.2016.06.003
      Issue No: Vol. 22 (2016)
       
  • Influence of measurement uncertainties on fractional solubility of iron in
           mineral aerosols over the oceans
    • Authors: Nicholas Meskhidze; Matthew S. Johnson; David Hurley; Kyle Dawson
      Pages: 85 - 92
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Nicholas Meskhidze, Matthew S. Johnson, David Hurley, Kyle Dawson
      The atmospheric supply of mineral dust iron (Fe) plays a crucial role in the Earth’s biogeochemical cycle and is of specific importance as a micronutrient in the marine environment. Observations show several orders of magnitude variability in the fractional solubility of Fe in mineral dust aerosols, making it hard to assess the role of mineral dust in the global ocean biogeochemical Fe cycle. In this study we compare the operational solubility of mineral dust aerosol Fe associated with the flow-through leaching protocol to the results of the global 3-D chemical transport model GEOS-Chem. According to the protocol, aerosol Fe is defined as soluble by first deionized water leaching of mineral dust through a 0.45μm pore size membrane followed by acidification and storage of the leachate over a long period of time prior to analysis. To estimate the uncertainty in soluble Fe results introduced by the flow-through leaching protocol, we prescribe an average 50% (range of 30–70%) fractional solubility to sub-0.45μm sized mineral dust particles that may inadvertently pass the filter and end up in the acidified (at pH∼1.7) leachate for a couple of month period. In the model, the fractional solubility of Fe is either explicitly calculated using a complex mineral aerosol Fe dissolution equations, or prescribed to be 1% and 4% often used by global ocean biogeochemical Fe cycle models to reproduce the broad characteristics of the presently observed ocean dissolved iron distribution. Calculations show that the fractional solubility of Fe derived through the flow-through leaching is higher compared to the model results. The largest differences (∼40%) are predicted to occur farther away from the dust source regions, over the areas where sub-0.45μm sized mineral dust particles contribute a larger fraction of the total mineral dust mass. This study suggests that different methods used in soluble Fe measurements and inconsistences in the operational definition of filterable Fe in marine environment and soluble Fe in atmospheric aerosols are likely to contribute to the wide range of fractional solubility of aerosol Fe reported in the literature.

      PubDate: 2016-07-29T22:01:25Z
      DOI: 10.1016/j.aeolia.2016.07.002
      Issue No: Vol. 22 (2016)
       
  • Iron oxide minerals in dust-source sediments from the Bodélé Depression,
           Chad: Implications for radiative properties and Fe bioavailability of dust
           plumes from the Sahara
    • Authors: Bruce M. Moskowitz; Richard L. Reynolds; Harland L. Goldstein; Thelma S. Berquó; Raymond F. Kokaly; Charlie S. Bristow
      Pages: 93 - 106
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Bruce M. Moskowitz, Richard L. Reynolds, Harland L. Goldstein, Thelma S. Berquó, Raymond F. Kokaly, Charlie S. Bristow
      Atmospheric mineral dust can influence climate and biogeochemical cycles. An important component of mineral dust is ferric oxide minerals (hematite and goethite) which have been shown to influence strongly the optical properties of dust plumes and thus affect the radiative forcing of global dust. Here we report on the iron mineralogy of dust-source samples from the Bodélé Depression (Chad, north-central Africa), which is estimated to be Earth’s most prolific dust producer and may be a key contributor to the global radiative budget of the atmosphere as well as to long-range nutrient transport to the Amazon Basin. By using a combination of magnetic property measurements, Mössbauer spectroscopy, reflectance spectroscopy, chemical analysis, and scanning electron microscopy, we document the abundance and relative amounts of goethite, hematite, and magnetite in dust-source samples from the Bodélé Depression. The partition between hematite and goethite is important to know to improve models for the radiative effects of ferric oxide minerals in mineral dust aerosols. The combination of methods shows (1) the dominance of goethite over hematite in the source sediments, (2) the abundance and occurrences of their nanosize components, and (3) the ubiquity of magnetite, albeit in small amounts. Dominant goethite and subordinate hematite together compose about 2% of yellow-reddish dust-source sediments from the Bodélé Depression and contribute strongly to diminution of reflectance in bulk samples. These observations imply that dust plumes from the Bodélé Depression that are derived from goethite-dominated sediments strongly absorb solar radiation. The presence of ubiquitous magnetite (0.002–0.57wt%) is also noteworthy for its potentially higher solubility relative to ferric oxide and for its small sizes, including PM<0.1μm. For all examined samples, the average iron apportionment is estimated at about 33% in ferric oxide minerals, 1.4% in magnetite, and 65% in ferric silicates. Structural iron in clay minerals may account for much of the iron in the ferric silicates. We estimate that the mean ferric oxides flux exported from the Bodélé Depression is 0.9Tg/yr with greater than 50% exported as ferric oxide nanoparticles (<0.1μm). The high surface-to-volume ratios of ferric oxide nanoparticles once entrained into dust plumes may facilitate increased atmospheric chemical and physical processing and affect iron solubility and bioavailability to marine and terrestrial ecosystems.

      PubDate: 2016-08-04T22:10:15Z
      DOI: 10.1016/j.aeolia.2016.07.001
      Issue No: Vol. 22 (2016)
       
  • Wind erosion reduces soil organic carbon sequestration falsely indicating
           ineffective management practices
    • Authors: Adrian Chappell; Jeffrey A. Baldock
      Pages: 107 - 116
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Adrian Chappell, Jeffrey A. Baldock
      Improved management of agricultural land has the potential to reduce greenhouse gas emissions and to reduce atmospheric CO2 via soil carbon sequestration. However, SOC stocks are reduced by soil erosion which is commonly omitted from calculations of crop production, C cycling, C sequestration and C accounting. We used fields from the wind eroded dryland cropping region of Western Australia to demonstrate the global implications for C sequestration and C accounting of omitting soil erosion. For the fields we previously estimated mean net (1950s–1990) soil erosion of 1.2±1.0tha−1 y−1. The mean net (1990–2013) soil erosion increased by nearly four times to 4.4±2.1tha−1 y−1. Conservation agriculture has evidently not reduced wind erosion in this region. The mean net (1990–2013) SOC erosion was up to 0.2tCha−1 y−1 across all sampled fields and similar to measured sequestration rates in the region (up to 0.5tCha−1 y−1; 10years) for many management practices recommended for building SOC stocks. The minimum detectable change (MDC; 10years) of SOC without erosion was up to 0.2tCha−1 y−1 whilst the MDC of SOC with erosion was up to 0.4tCha−1 y−1. These results illustrate the generally applicable outcome: (i) if SOC erosion is equal to (or greater than) the increase in SOC due to management practices, the change will not be detectable (or a loss will be evident); (ii) without including soil erosion in SOC sequestration calculations, the monitoring of SOC stocks will lead to, at best the inability to detect change and, at worst the false impression that management practices have failed to store SOC. Furthermore, continued omission of soil erosion in crop production, C accounting and C sequestration will most likely undermine confidence in policy designed to encourage adoption of C farming and the attendant benefits for soil stewardship and food security.

      PubDate: 2016-08-04T22:10:15Z
      DOI: 10.1016/j.aeolia.2016.07.005
      Issue No: Vol. 22 (2016)
       
  • Quantifying the provenance of aeolian sediments using multiple composite
           fingerprints
    • Authors: Benli Liu; Qinghe Niu; Jianjun Qu; Ruiping Zu
      Pages: 117 - 122
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Benli Liu, Qinghe Niu, Jianjun Qu, Ruiping Zu
      We introduce a new fingerprinting method that uses multiple composite fingerprints for studies of aeolian sediment provenance. We used this method to quantify the provenance of sediments on both sides of the Qinghai-Tibetan Railway (QTR) in the Cuona Lake section of the Tibetan Plateau (TP), in an environment characterized by aeolian and fluvial interactions. The method involves repeatedly solving a linear mixing model based on mass conservation; the model is not limited to spatial scale or transport types and uses all the tracer groups that passed the range check, Kruskal-Wallis H-test, and a strict analytical solution screening. The proportional estimates that result from using different composite fingerprints are highly variable; however, the average of these fingerprints has a greater accuracy and certainty than any single fingerprint. The results show that sand from the lake beach, hilly surface, and gullies contribute, respectively, 48%, 31% and 21% to the western railway sediments and 43%, 33% and 24% to the eastern railway sediments. The difference between contributions from various sources on either side of the railway, which may increase in the future, was clearly related to variations in local transport characteristics, a conclusion that is supported by grain size analysis. The construction of the QTR changed the local cycling of materials, and the difference in provenance between the sediments that are separated by the railway reflects the changed sedimentary conditions on either side of the railway. The effectiveness of this method suggests that it will be useful in other studies of aeolian sediments.

      PubDate: 2016-08-09T22:16:09Z
      DOI: 10.1016/j.aeolia.2016.08.002
      Issue No: Vol. 22 (2016)
       
  • A note on the stochastic nature of particle cohesive force and
           implications to threshold friction velocity for aerodynamic dust
           entrainment
    • Authors: Yaping Shao; Martina Klose
      Pages: 123 - 125
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Yaping Shao, Martina Klose
      There is considerable interest to determine the threshold for aeolian dust emission on Earth and Mars. Existing schemes for threshold friction velocity are all deterministic in nature, but observations show that in the dust particle size range the threshold friction velocity scatters strongly due to stochastic inter-particle cohesion. In the real world, there always exists a certain amount of free dust which can be easily lifted from the surface by weak winds or even turbulence, as exemplified by dust devils. It has been proposed in the dust-devil research community, that the pressure drop at dust-devil center may be a major mechanism for dust-devil dust emission, known as the Δp effect. It is questioned here whether the Δp effect is substantial or whether the elevated dust concentration in dust devils is due to free dust emission. A simple analysis indicates that the Δp effect appears to be small and the dust in dust devils is probably due to free dust emission and dust convergence. To estimate free dust emission, it is useful to define a lower limit of dust-particle threshold friction velocity. A simple expression for this velocity is proposed by making assumptions to the median and variance of inter-particle cohesive force. The simple expression is fitted to the data of the Arizona State University Vortex Generator. While considerable uncertainty remains in the scheme, this note highlights the need for additional research on the stochastic nature of dust emission.

      PubDate: 2016-08-19T10:37:35Z
      DOI: 10.1016/j.aeolia.2016.08.004
      Issue No: Vol. 22 (2016)
       
  • A review of Computational Fluid Dynamics (CFD) airflow modelling over
           aeolian landforms
    • Authors: Thomas A.G. Smyth
      Pages: 153 - 164
      Abstract: Publication date: September 2016
      Source:Aeolian Research, Volume 22
      Author(s): Thomas A.G. Smyth
      Aeolian landforms occur on all earths’ continents as well as on Mars, Titan and Venus and are typically formed where sediment is eroded and/or deposited by near surface wind flow. As wind flow approaches an aeolian landform, secondary flow patterns are created that cause wind to deviate in both speed and direction, producing complex patterns of sediment erosion, deposition and transportation. Computational Fluid Dynamics (CFD) modelling of wind flow has become a common tool to predict and understand secondary wind flow and resulting sediment transport. Its use has progressed from simulating wind flow over simple two dimensional dune shapes, to calculating a multitude of flow parameters over a range of increasingly complex landforms. Analysis of 25 peer reviewed journal articles, found that CFD has been crucial to providing additional insight to flow dynamics on the stoss slope of dunes, the structure and nature of wind flow separation in the lee of landforms and information on localised wind flow variations in large-scale dune fields. The findings of this assay demonstrate that further research is required regarding the parameterisation and modelling of surface roughness, the incorporation of accurate sediment transport to wind flow models, and the prediction of topographic surface changes. CFD is anticipated to be increasingly utilised in aeolian geomorphology and this work aims to be a starting point for aeolian geomorphologists wishing to better understand and review the utilisation of the technique to date.

      PubDate: 2016-09-03T16:55:37Z
      DOI: 10.1016/j.aeolia.2016.07.003
      Issue No: Vol. 22 (2016)
       
  • Our evolving understanding of aeolian bedforms, based on observation of
           dunes on different worlds
    • Authors: Serina Diniega; Mikhail Krevalevsky; Jani Radebaugh; Simone Silverstro; Matt Telfer; Daniela Tirsch
      Abstract: Publication date: Available online 24 October 2016
      Source:Aeolian Research
      Author(s): Serina Diniega, Mikhail Krevalevsky, Jani Radebaugh, Simone Silverstro, Matt Telfer, Daniela Tirsch
      Dunes, dune fields, and ripples are unique and useful records of the interaction between wind and granular materials – finding such features on a planetary surface immediately suggests certain information about climate and surface conditions (at least during the dunes’ formation and evolution). Additionally, studies of dune characteristics under non-Earth conditions allow for “tests” of aeolian process models based primarily on observations of terrestrial features and dynamics, and refinement of the models to include consideration of a wider range of environmental and planetary conditions. To-date, the planetary aeolian community has found and studied dune fields on Mars, Venus, and the Saturnian moon Titan. Additionally, we have observed candidate “aeolian bedforms” on Comet 67P/Churyumov-Gerasimenko, the Jovian moon Io, and – most recently – Pluto. In this paper, we hypothesize that the progression of investigations of aeolian bedforms and processes on a particular planetary body follows a consistent sequence – primarily set by the acquisition of data of particular types and resolutions, and by the maturation of knowledge about that planetary body. We define that sequence of generated knowledge and new questions (within seven investigation phases) and discuss examples from all of the studied bodies. The aim of such a sequence is to better define our past and current state of understanding about the aeolian bedforms of a particular body, to highlight the related assumptions that require re-analysis with data acquired during later investigations, and to use lessons learned from planetary and terrestrial aeolian studies to predict what types of investigations could be most fruitful in the future.

      PubDate: 2016-10-25T11:20:54Z
      DOI: 10.1016/j.aeolia.2016.10.001
       
  • Aeolian dune sediment flux heterogeneity in Meridiani Planum, Mars
    • Authors: Matthew Chojnacki; Anna Urso; Lori K. Fenton; Timothy I. Michaels
      Abstract: Publication date: Available online 5 October 2016
      Source:Aeolian Research
      Author(s): Matthew Chojnacki, Anna Urso, Lori K. Fenton, Timothy I. Michaels
      It is now known unambiguously that wind-driven bedform activity is occurring on the surface of Mars today, including early detections of active sand dunes in Meridiani Planum’s Endeavour crater. Many of these reports are only based on a few sets of observations of relatively isolated bedforms and lack regional context. Here, we investigate aeolian activity across central Meridiani Planum and test the hypothesis that dune sites surrounding Endeavour crater are also active and part of region-wide sediment migration driven by northwesterly winds. All 13 dune fields investigated clearly showed evidence for activity and the majority exhibited dune migration (average rates of 0.6m/Earth-year). Observations indicate substantial geographic and temporal heterogeneity of dune crest fluxes across the area and per site. Locations with multiple time steps indicate dune sand fluxes can vary by a factor of five, providing evidence for short periods of rapid migration followed by near-stagnation. In contrast, measurements at other sites are nearly identical, indicating that some dunes are in a steady-state as they migrate. The observed sediment transport direction was consistent with a regional northeasterly-to-northwesterly wind regime, revealing more variations than were appreciated from earlier, more localized studies. Craters containing shallow, degraded, flat-floored interiors tended to have dunes with high sediment fluxes/activity, whereas local kilometer-scale topographic obstructions (e.g., central peaks, yardangs) were found to be inversely correlated with dune mobility. Finally, the previous, more limited detections of dune activity in Endeavour crater have been shown to be representative of a broader, region-wide pattern of dune motion.

      PubDate: 2016-10-11T17:48:41Z
      DOI: 10.1016/j.aeolia.2016.07.004
       
  • The albedo of martian dunes: Insights into aeolian activity and dust devil
           formation
    • Authors: K.A. Bennett; L. Fenton; J.F. Bell
      Abstract: Publication date: Available online 10 September 2016
      Source:Aeolian Research
      Author(s): K.A. Bennett, L. Fenton, J.F. Bell
      Wind is the primary geologic process currently active on the surface of Mars. Albedo variations at eight dune fields were tested based on the hypothesis that a dune’s ripple migration rate is correlated to its albedo. On Mars, where the atmospheric pressure is low, dust is removed from the surface of a dune by saltating sand. Therefore, more active dunes should remove dust more efficiently than less active dunes. A dune’s albedo was found to be low in the first half of the Mars year (Ls =0–180°) and high in the second half (Ls =180–360°) during the dusty season. Both dunes with fast- and slow-moving ripples exhibit low albedos, whereas dunes with ripples that migrate at intermediate speeds exhibit high albedos. A dune’s minimum albedo does not have a simple correlation with its ripple migration rate. Instead, we propose that dust devils remove dust on slow-moving and immobile dunes, whereas saltating sand caused by strong winds removes dust on faster dunes. Albedo should not be used as a proxy for migration rate of ripples or dune activity, as it may be difficult to distinguish between fast- and slow-moving ripples on dunes that have the same albedo. The presence of dust devil tracks on a dune could indicate the dune and/or its ripples are either immobile or migrating slowly. We also propose that albedo variations on individual dune fields can reveal insight into the local wind regime.

      PubDate: 2016-09-17T17:07:59Z
      DOI: 10.1016/j.aeolia.2016.08.009
       
 
 
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